CN111432870B

CN111432870B - Guide wire

Info

Publication number: CN111432870B
Application number: CN201880078699.XA
Authority: CN
Inventors: 牛田圭亮
Original assignee: Asahi Intecc Co Ltd
Current assignee: Asahi Intecc Co Ltd
Priority date: 2018-02-07
Filing date: 2018-02-07
Publication date: 2022-08-30
Anticipated expiration: 2038-02-07
Also published as: JP6933734B2; EP3750587B1; WO2019155550A1; CN111432870A; US20200289795A1; JPWO2019155550A1; US11969564B2; KR20200117980A; EP3750587A4; EP3750587A1

Abstract

The invention provides a guide wire which is easy to manufacture and has smooth performance and flexibility of the front end of the guide wire. In a guide wire (1) provided with a core shaft (9), a coil body (3) covering the tip end of the core shaft (9), and a coating agent (7) covering the outer periphery of the coil body (3), the coil body (3) is provided with a tip-side coil body (3a) on the tip side and a base-side coil body (3b) disposed on the base end side of the tip-side coil body (3a), and the surface roughness of the base-side coil body (3b) is made larger than the surface roughness of the tip-side coil body (3 a).

Description

Guide wire

Technical Field

The present invention relates to a medical guide wire.

Background

Conventionally, various guide wires for guiding catheters and the like used by being inserted into tubular organs such as blood vessels, digestive tracts and ureters and tissues in vivo have been proposed for treatment and examination. For example, patent document 1 describes a guide wire including: a guidewire body; a coil body covering the distal end portion of the guide wire main body and including a distal end side coil body and a proximal end side coil body; and a resin coating layer (see fig. 1 and the like) provided on the outer periphery of the coil body including the distal-side coil body and the proximal-side coil body.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-135645

The invention content is as follows:

problems to be solved by the invention

Generally, a resin coating layer covering the outer periphery of a guide wire improves the operability of the guide wire by reducing the friction of the guide wire and improving the sliding property. This is also described in the resin coating layer described in patent document 1 (see paragraph 0116).

However, since the resin coating layer described in patent document 1 is formed in a substantially uniform film thickness over the entire coil body, the entire coil body has the same slidability and flexibility, and when the entire coil is formed in a thick film thickness, the flexibility of the coil tip is impaired, and when the entire coil is formed in a thin film thickness, the slidability is impaired on the coil base end side.

In addition, although it is also conceivable to set a good film thickness on the entire coil, there is a problem that the allowable range of such a good film thickness is extremely small, and the yield is lowered in manufacturing the wire.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a guide wire which is easy to manufacture and which can achieve both the smoothness of the guide wire and the flexibility of the distal end of the guide wire.

Means for solving the problems

In order to solve the above problem, a first aspect of the present invention is a guide wire including: a mandrel; a coil body covering the front end of the core shaft; and a coating agent covering an outer periphery of the coil body, wherein the coil body includes a distal-side coil body and a proximal-side coil body disposed on a proximal side of the distal-side coil body, and a surface roughness of the proximal-side coil body is made larger than a surface roughness of the distal-side coil body.

In addition, according to a second aspect of the present invention, in the guide wire according to the first aspect, a groove portion extending in a longitudinal direction of a wire material constituting the base end side coil body is formed on a surface of the base end side coil body.

A third aspect of the present invention is the guidewire according to the first or second aspect, wherein the wire rod constituting the base end side coil body has a rectangular shape in a cross-sectional view.

A fourth aspect of the present invention is the guide wire according to the third aspect, wherein the wire rod constituting the distal-side coil body has a circular shape in a cross-sectional view.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the first aspect of the present invention, in the guide wire including the core shaft, the coil body covering the tip end portion of the core shaft, and the coating agent covering the outer periphery of the coil body, the coil body includes the tip side coil body on the tip side and the base side coil body disposed on the base end side of the tip side coil body, and the surface roughness of the base side coil body is made larger than the surface roughness of the tip side coil body, so that when the coating agent is applied to the surface of the coil body, the coating film having high adhesion to the base side coil body is formed thick on the base end side of the coil body, whereby the smoothness of the guide wire can be improved, and the coating film is formed thin on the tip side coil body on the tip end side of the coil body, whereby the tip flexibility of the guide wire can be improved.

Further, according to a second aspect of the present invention, in the guide wire according to the first aspect, since the groove portion along the longitudinal direction of the wire rod constituting the base end side coil body is formed on the surface of the base end side coil body, in addition to the effect of the guide wire according to the first aspect, the base end side coil body having a large surface roughness can be formed only by passing the wire rod constituting the base end side coil body through a die having a convex-concave inner periphery, and the smoothness of the guide wire can be improved by simply forming a coating film having high adhesion to the base end side coil body to be thick on the base end side of the coil body, and the flexibility of the tip end of the guide wire can be improved by forming the coating film to be thin on the tip end side coil body on the tip end side of the coil body.

Further, according to a third aspect of the present invention, in the guide wire according to the first or second aspect, since the wire rod constituting the base end side coil body has a rectangular shape in a cross-sectional view, in addition to the effect of the guide wire according to the first or second aspect, when the inner diameter of the tip side coil body is made to coincide with the inner diameter of the base end side coil body, the thickness of the coating film of the base end side coil body can be formed to be further thick.

Further, according to a fourth aspect of the present invention, in the guide wire according to the third aspect, since the wire rods constituting the tip side coil body have a circular shape in a cross-sectional view, in addition to the effect of the guide wire according to the third aspect, the wire rods constituting the tip side coil body tend to be in point contact with each other, and therefore, the flexibility of the tip end of the guide wire can be further ensured.

Drawings

Fig. 1 is a schematic configuration diagram of a guide wire according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of the leading end of the guide wire of the first embodiment.

Fig. 3 is an enlarged view of the leading end of the guide wire of the second embodiment.

Fig. 4 is a longitudinal cross-sectional view of the leading end of the guide wire of the second embodiment.

Fig. 5 is an enlarged view of the leading end of the guide wire of the third embodiment.

Fig. 6 is an enlarged view of the tip of the guide wire of the fourth embodiment.

Fig. 7 is a longitudinal cross-sectional view of the distal end of the guide wire of the fourth embodiment.

Fig. 8 is a longitudinal cross-sectional view of the distal end of the guide wire of the fifth embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(first embodiment)

First, a first embodiment of the present invention will be explained.

Fig. 1 is a schematic configuration diagram of a guide wire according to a first embodiment of the present invention, and fig. 2 is an enlarged view of a distal end of the guide wire according to the first embodiment.

As shown in fig. 1, the guide wire 1 of the present embodiment is composed of a core shaft 9, a coil body 3 covering the tip end portion of the core shaft 9, and a coating agent 7 covering the outer periphery of the coil body 3.

The mandrel 9 is a rod-shaped member having a circular cross section and a diameter decreasing from the base end to the tip end, and is an elongated flexible member. The material of the mandrel 9 is not particularly limited as long as it is a biocompatible material such as stainless steel, Ni — Ti alloy, cobalt alloy, or the like, but stainless steel is used in the present embodiment.

The coil body 3 is a cylindrical hollow coil body formed by winding a single or a plurality of metal wire rods, and the tip thereof is fastened to the core shaft 9 by the brazing material 2, and the base end of the coil body 3 is fastened to the core shaft 9 by the brazing material 4.

The coil body 3 of the present embodiment is formed of two coil bodies, a tip-side coil body 3a on the tip side and a base-side coil body 3b arranged on the base end side of the tip-side coil body 3 a. The tip-side coil body 3a of the present embodiment is a coil body located on the tip side of the coil body 3 from the intermediate position a of the coil body 3, and the base-side coil body 3b of the present embodiment is a coil body located on the base side of the intermediate position a of the coil body 3.

In the present embodiment, the surface roughness of the base-side coil body 3b is larger than the surface roughness of the tip-side coil body 3 a. In fig. 1 and 2, the region of the base-side coil body 3b is shown in hatching in order to show that the surface roughness of the base-side coil body 3b is larger than the surface roughness of the tip-side coil body 3 a.

The surface roughness can be adjusted by, for example, masking a portion of the distal-side coil body 3a of the coil body 3 and then subjecting the entire coil body 3 to a known surface treatment such as injection molding, so that the surface roughness of the proximal-side coil body 3b can be made larger than the surface roughness of the distal-side coil body 3 a.

The material of the wire rods forming the coil body 3 is not particularly limited as long as it is a biocompatible material such as tungsten or a Ni — Ti alloy, but in the present embodiment, stainless steel is used, and the material of the wire rods forming the tip side coil body 3a and the base side coil body 3b is the same stainless steel.

The solder 2 and the solder 4 are not particularly limited as long as they are biocompatible solders such as gold-tin solder and silver-tin solder, but silver-tin solder is used in the present embodiment.

As described above, the coating agent 7 covers the outer peripheries of the coil body 3 and the core shaft 9, but as shown in fig. 1 and 2, the coating agent 7 of the present embodiment has a greater film thickness in the region of the base-side coil body 3b located closer to the base end than the intermediate position a of the coil body 3 than in the region of the tip-side coil body 3a located closer to the tip end than the intermediate position a of the coil body 3.

In the present embodiment, the difference between the film thickness of the region of the base-side coil body 3b and the film thickness of the region of the tip-side coil body 3a is about several μm to 10 μm, but is illustrated in fig. 1 and 2 in an exaggerated manner for easy understanding.

In the present embodiment, the reason why the film thickness of the base-side coil body 3b is thicker than the film thickness of the tip-side coil body 3a is that the surface roughness of the base-side coil body 3b is larger than the surface roughness of the tip-side coil body 3a, and thus the film thickness of the base-side coil body 3b is automatically thicker than the film thickness of the tip-side coil body 3a when the coating agent 7 is applied to the surface of the coil body 3.

In this case, by making the surface roughness of the base-side coil body 3b large, the adhesion between the base-side coil body 3b and the coating agent 7 becomes high, and the smoothness of the guidewire 1 can be improved.

On the other hand, by forming the coating agent 7 thinly on the distal end side coil body 3a on the distal end side of the coil body 3, the distal end flexibility of the guide wire 1 can be ensured.

Further, for example, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyacrylamide, polyacrylic acid, sodium polyacrylate, poly (2-hydroxyethyl methacrylate), maleic anhydride copolymer, ethylene-vinyl alcohol copolymer, monomer of 2-methacryloyloxyethyl phosphorylcholine or a copolymer thereof, (2-hydroxyethyl methacrylate) -styrene block copolymer, various synthetic polypeptides, collagen, hyaluronic acid, cellulose-based polymers, and a mixture thereof are preferably used as the coating agent 7.

According to the guide wire 1 of the present embodiment, the core shaft 9, the coil body 3 covering the tip end portion of the core shaft 9, and the coating agent 7 covering the outer periphery of the coil body 3 are provided, and the coil body 3 is provided with the tip side coil body 3a on the tip side and the base side coil body 3b arranged on the base end side of the tip side coil body 3a, and since the surface roughness of the base side coil body 3b is made larger than the surface roughness of the tip side coil body 3a, when the coating agent 7 is applied to the surface of the coil body 3, a coating film having high adhesion to the base side coil body 3b is formed thick on the base end side of the coil body 3, and the smoothness of the guide wire 1 is improved, and the tip flexibility of the guide wire 1 can be ensured by forming the coating film thin on the tip side coil body 3a on the tip side of the coil body 3.

(second embodiment)

A second embodiment of the present invention will be described below.

Fig. 3 is an enlarged view of the distal end of the guide wire according to the second embodiment, and fig. 4 is a longitudinal sectional view of the distal end of the guide wire according to the second embodiment.

In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 3, the guide wire 10 of the present embodiment is composed of a core shaft 9, a coil body 13 covering the tip end portion of the core shaft 9, and a coating agent 17 covering the outer periphery of the coil body 13.

The coil body 13 is a cylindrical hollow coil body formed by winding a single or a plurality of metal wire rods, and the tip thereof is fastened to the core shaft 9 by the brazing material 2, and the base end of the coil body 3 is fastened to the core shaft 9 by the brazing material 4.

The coil body 13 of the present embodiment is formed of two coil bodies, a tip-side coil body 13a on the tip side and a base-side coil body 13b arranged on the base end side of the tip-side coil body 13 a. Further, since the distal ends of the wires constituting the base end side coil bodies 13b in the embodiment are connected to the base ends of the wires constituting the distal end side coil bodies 13a, as shown in fig. 3 and 4, the boundary lines between the distal end side coil bodies 13a and the base end side coil bodies 13b are inclined obliquely along the torsion angle of the coil bodies 13.

In the present embodiment, the hardness of the distal-side coil body 13a is lower than that of the proximal-side coil body 13 b. In fig. 3 and 4, as described later, the region of the base-side coil body 13b is shown in hatching in order to show the point that the surface roughness of the base-side coil body 13b is larger than the surface roughness of the tip-side coil body 13 a.

The material of the wire forming the coil body 13 may be the same as that of the coil body 3 of the first embodiment, but in this embodiment, platinum is used for the tip-side coil body 13a, and stainless steel is used for the base-side coil body 13 b.

The distal-side coil body 13a is not limited as long as it has a lower hardness than the proximal-side coil body 13 b. For example, as described above, the hardness can be changed by wire drawing or heat treatment even in the same kind of metal, although the metal can be a different kind of metal such as platinum or stainless steel.

As described above, the coating agent 17 covers the outer peripheries of the coil body 13 and the core shaft 9, but as shown in fig. 3 and 4, the coating agent 17 of the present embodiment has a greater film thickness in the region of the base end side coil body 13b than in the region of the coil body 13 a.

In the present embodiment, the difference between the film thickness of the region of the base-side coil body 13b and the film thickness of the region of the tip-side coil body 13a is about several μm to 10 μm, but is shown exaggerated in fig. 3 and 4 for easy understanding.

In the present embodiment, the reason why the film thickness in the region of the base-side coil body 13b is thicker than the film thickness in the region of the tip-side coil body 13a is that the surface roughness of the base-side coil body 13b is larger than the surface roughness of the tip-side coil body 13 a.

In order to make the surface roughness of the base-side coil body 13b larger than the surface roughness of the tip-side coil body 13a in the present embodiment, the coil body 13 is subjected to the following processing.

That is, in the process of wire drawing using a die, scratches (irregularities) are generated on the surfaces of the wire rods constituting the base-end side coil body 13b and the tip-end side coil body 13 a. By smoothing the distal-side coil body 13a having a lower hardness than the proximal-side coil body 13b by forging, the surface roughness of the proximal-side coil body 13b can be made larger than the surface roughness of the distal-side coil body 13 a.

Therefore, in fig. 3 and 4, the base-side coil body 13b is illustrated in a hatched manner, and the tip-side coil body 13a is not illustrated in a hatched manner, but this does not mean that the surface of the tip-side coil body 13a is flat, but means that the surface roughness of the tip-side coil body 13a is smaller than that of the base-side coil body 13 b.

Then, when the coating agent 17 is applied to the surface of the coil body 13, the film thickness of the region of the base-end side coil body 13b automatically becomes thicker than the film thickness of the region of the tip-end side coil body 13 a.

In this case, since the surface roughness of the base-side coil body 13b is large, the adhesion between the base-side coil body 13b and the coating film 17 is high, and the smoothness of the guidewire 10 can be improved.

On the other hand, the coating film 17 is formed thinly on the distal-end-side coil body 13a on the distal end side of the coil body 13, whereby the distal end flexibility of the guide wire 10 can be secured.

Further, the same material as the coating agent 7 of the first embodiment can be used for the coating agent 17.

According to the guidewire 10 of the present embodiment, the mandrel 9, the coil body 13 covering the tip end portion of the mandrel 9, and the coating agent 17 covering the outer periphery of the coil body 13 are provided, and the coil body 13 includes the tip-side coil body 13a on the tip end side and the base-side coil body 13b disposed on the base end side of the tip-side coil body 13a, and since the hardness of the tip-side coil body 13a is made lower than that of the base-side coil body 13b, the surface roughness of the base-side coil body 13b can be easily made larger than that of the tip-side coil body 13 a. Therefore, the smoothness of the guide wire 10 is improved by simply forming a thick coating film having high adhesion to the base-side coil body 13b on the base end side of the coil body 13, and the flexibility of the tip of the guide wire 10 can be ensured by forming a thin coating film on the tip-side coil body 13a on the tip end side of the coil body 13.

(third embodiment)

A third embodiment of the present invention will be explained below.

As shown in fig. 5, the guide wire 20 of the present embodiment is composed of a core shaft 9, a coil body 23 covering the tip end portion of the core shaft 9, and a coating agent 27 covering the outer periphery of the coil body 23.

The coil body 23 is a cylindrical hollow coil body formed by winding a single or a plurality of metal wire rods, and the tip thereof is fastened to the core shaft 9 with a brazing material 2, and the base end of the coil body 23 is fastened to the core shaft 9 with a brazing material 4.

The coil body 23 of the present embodiment is formed of two coil bodies, a tip-side coil body 23a on the tip side and a base-side coil body 23b arranged on the base end side of the tip-side coil body 23 a. Further, since the distal ends of the wire rods constituting the base end side coil bodies 23b in the embodiment are connected to the base ends of the wire rods constituting the tip end side coil bodies 23a, as shown in fig. 5, the boundary lines between the tip end side coil bodies 23a and the base end side coil bodies 23b are inclined obliquely along the torsion angle of the coil bodies 23.

In the present embodiment, as shown in fig. 5, a plurality of grooves 25 are formed in the base-side coil body 23b along the longitudinal direction of the wire material constituting the base-side coil body 23 b.

The groove 25 may be formed on the entire surface of the wire rod constituting the base-end side coil body 23b, or may be formed on a part of the surface of the wire rod constituting the base-end side coil body 23 b. However, when the groove portion 25 is formed on the entire surface of the wire rod constituting the base-end side coil body 23b, the thickness of the coating agent described later can be increased.

The material of the wire forming the coil body 23 may be the same as that of the coil body 3 of the first embodiment, and in the present embodiment, the same stainless steel is used for the tip-side coil body 23a and the base-side coil body 23 b.

As described above, the coating agent 27 covers the outer peripheries of the coil body 23 and the core shaft 9, but as shown in fig. 5, the coating agent 27 of the present embodiment has a film thickness in the region of the base end side coil body 23b larger than the film thickness in the region of the coil body 23 a.

In the present embodiment, the difference between the film thickness of the region of the base-side coil body 23b and the film thickness of the region of the tip-side coil body 23a is also about several μm to 10 μm, but is illustrated in an exaggerated manner in fig. 5 for easy understanding.

In the present embodiment, the reason why the thickness of the region of the base-side coil body 23b is thicker than the thickness of the region of the tip-side coil body 23a is that a plurality of grooves 25 are formed in the longitudinal direction on the surface of the wire material constituting the base-side coil body 23 b. In other words, the reason is that the surface roughness of the base-end side coil body 23b is larger than the surface roughness of the tip-end side coil body 23 a.

Therefore, when the coating agent 27 is applied to the surface of the coil body 23, the film thickness of the base-side coil body 23b is automatically made thicker than the film thickness of the tip-side coil body 23 a.

Further, by forming a plurality of groove portions 25 in the longitudinal direction on the surface of the wire rod constituting the base end side coil body 23b, the adhesion between the base end side coil body 23b and the coating agent 27 is increased, and the smoothness of the guide wire 20 can be improved.

On the other hand, by forming the coating agent 27 thinly on the distal end side coil body 23a on the distal end side of the coil body 23, the distal end flexibility of the guide wire 20 can be ensured.

Further, the same material as the coating agent 7 of the first embodiment can be used for the coating agent 27.

According to the guidewire 20 of the present embodiment, since the wire body 23 includes the core 9, the coil body 23 covering the tip end portion of the core 9, and the coating agent 27 covering the outer periphery of the coil body 23, and the coil body 23 includes the tip-side coil body 23a on the tip side and the base-side coil body 23b arranged on the base end side of the tip-side coil body 23a, and the groove portion 25 along the longitudinal direction of the wire rod constituting the base-side coil body 23b is formed on the surface of the base-side coil body 23b, the base-side coil body 23b having a large surface roughness can be formed only by passing the wire rod constituting the base-side coil body 23b through a die having a concave-convex inner periphery, the smoothness of the guidewire 20 can be improved by simply forming a thick coating film having high adhesion to the base-side coil body 23b on the base end side of the coil body 23, and the coating film can be formed thinly to the tip-side coil body 23a on the tip side of the coil body 23, thereby, the flexibility of the distal end of the guide wire 20 can be improved.

In the present embodiment, the tip-side coil body 23a and the base-side coil body 23b have been described as being constructed of the same stainless steel, but as in the second embodiment, the hardness of the tip-side coil body 23a may be made lower than the hardness of the base-side coil body 23b, and the groove portions 25 may be formed in the longitudinal direction of the wire rods constituting the base-side coil body 23b, or as in the first embodiment, a known surface treatment method such as an injection process may be performed on the entire coil body 23 after masking portions of the tip-side coil body 23a of the coil body 23.

In this case, in addition to the effects of the guide wire 20 of the present embodiment, the guide wire of the first embodiment and the guide wire of the second embodiment can also have the effects. For example, the base-side coil body 23b having a large surface roughness can be easily formed by simply passing the wire material constituting the base-side coil body 23b through a die having a concave-convex inner periphery, and when the surface roughness of the entire coil body 23 is formed under the same condition, the surface roughness of the base-side coil body 23b can be easily made larger than the surface roughness of the tip-side coil body 23 a.

(fourth embodiment)

A fourth embodiment of the present invention will be explained below.

Fig. 6 is an enlarged view of the distal end of the guide wire according to the fourth embodiment, and fig. 7 is a longitudinal sectional view of the distal end of the guide wire according to the fourth embodiment.

As shown in fig. 6, the guide wire 30 of the present embodiment is composed of a core shaft 9, a coil body 33 covering the tip end portion of the core shaft 9, and a coating agent 37 covering the outer periphery of the coil body 33.

The coil body 33 is a cylindrical hollow coil body formed by winding a single or a plurality of metal wire rods, and the tip thereof is fastened to the core shaft 9 by the brazing material 2, and the base end of the coil body 3 is fastened to the core shaft 9 by the brazing material 4.

The coil body 33 of the present embodiment is formed of two coil bodies, a tip-side coil body 33a on the tip side and a base-side coil body 33b arranged on the base end side of the tip-side coil body 33 a. Further, since the distal ends of the wires constituting the base-side coil body 33b in the embodiment are connected to the proximal ends of the wires constituting the distal-side coil body 33a, as shown in fig. 6 and 7, the boundary line between the distal-side coil body 33a and the base-side coil body 33b appears to be inclined obliquely along the torsion angle of the coil body 33.

In the present embodiment, the surface roughness of the base-side coil body 33b is larger than the surface roughness of the tip-side coil body 33 a. In fig. 6 and 7, the region of the base-side coil body 33b is shown in hatching in order to show that the surface roughness of the base-side coil body 33b is larger than the surface roughness of the tip-side coil body 33 a.

The wire members constituting the distal-side coil body 33a and the proximal-side coil body 33b are each rectangular in shape in a transverse cross section.

The material of the wire forming the coil body 33 may be the same as that of the coil body 3 of the first embodiment, and in the present embodiment, the same stainless steel is used for the distal-side coil body 33a and the proximal-side coil body 33 b.

As described above, the coating agent 37 covers the outer peripheries of the coil body 33 and the core shaft 9, but as shown in fig. 6 and 7, the coating agent 37 of the present embodiment has a greater film thickness in the region of the base-side coil body 33b than in the region of the tip-side coil body 33 a.

In the present embodiment, the difference between the film thickness of the region of the base-side coil element 33b and the film thickness of the region of the tip-side coil element 33a is also about several μm to 10 μm, but is exaggerated in fig. 6 and 7 for easy understanding.

In the present embodiment, the reason why the film thickness in the region of the base-side coil body 33b is thicker than the film thickness in the region of the tip-side coil body 33a is that the surface roughness of the base-side coil body 33b is larger than the surface roughness of the tip-side coil body 33 a.

Therefore, when the coating agent 37 is applied to the surface of the coil body 33, the film thickness of the region of the base-side coil body 33b automatically becomes thicker than the film thickness of the region of the tip-side coil body 33 a.

Further, the adhesion between the base end side coil body 33b and the coating film 37 is increased, and the smoothness of the guide wire 30 can be improved.

On the other hand, by forming the coating film 37 thinly on the distal-end-side coil body 33a on the distal end side of the coil body 33, the distal end flexibility of the guide wire 30 can be ensured.

Further, the same material as the coating agent 7 of the first embodiment can be used for the coating agent 37.

According to the guide wire 30 of the present embodiment, since the core wire 9, the coil body 33 covering the tip end portion of the core wire 9, and the coating agent 37 covering the outer periphery of the coil body 33 are provided, the coil body 33 includes the tip-side coil body 33a on the tip side and the base-side coil body 33b arranged on the base end side of the tip-side coil body 33a, and the wire rods constituting the tip-side coil body 33a and the base-side coil body 33b are rectangular in a cross-sectional view, the coating film of the base-side coil body 33b can be formed to be at least thicker.

In particular, when the cross-sectional shape of the distal-side coil body 33a is a circular shape, the effect is remarkable when the inner diameter thereof is made to coincide with the inner diameter of the proximal-side coil body 33 b.

In the present embodiment, the tip-side coil body 33a and the base-side coil body 33b are described as being configured of the same stainless steel, but the hardness of the tip-side coil body 33a may be made lower than that of the base-side coil body 33b as in the second embodiment, a groove portion may be formed in the longitudinal direction of the wire material configuring the base-side coil body 33b as in the third embodiment, or a known surface treatment method such as an injection process may be performed on the entire coil body 33 after covering the portion of the tip-side coil body 33a of the coil body 33 as in the first embodiment.

In this case, in addition to the effects of the guide wire 30 of the present embodiment, the effects of the guide wire of the first embodiment to the guide wire of the third embodiment can be obtained.

(fifth embodiment)

A fifth embodiment of the present invention will be explained below.

As shown in fig. 8, the guide wire 40 of the present embodiment is composed of a core shaft 9, a coil body 43 covering the tip end portion of the core shaft 9, and a coating agent 47 covering the outer periphery of the coil body 43.

The coil body 43 is a cylindrical hollow coil body formed by winding a single or a plurality of metal wire rods, and the tip end thereof is fastened to the core shaft 9 by the brazing material 2, and the base end of the coil body 3 is fastened to the core shaft 9 by the brazing material 4.

The coil body 43 of the present embodiment is formed of two coil bodies, a distal-side coil body 43a on the distal side and a base-side coil body 43b arranged on the base end side of the distal-side coil body 43 a. Further, since the distal end of the wire rod constituting the base end side coil body 43b in the embodiment is connected to the proximal end of the wire rod constituting the distal end side coil body 43a, as shown in fig. 8, the boundary line between the distal end side coil body 43a and the base end side coil body 43b appears to be inclined obliquely along the torsion angle of the coil body 43.

In the present embodiment, the surface roughness of the base-end side coil body 43b is larger than the surface roughness of the tip-end side coil body 43 a. In fig. 8, the region of the base-side coil body 43b is shown in hatching in order to show that the surface roughness of the base-side coil body 43b is larger than the surface roughness of the tip-side coil body 43 a.

The wire rod constituting the distal-side coil body 43a has a circular shape in a cross-sectional view, and the wire rod constituting the proximal-side coil body 43b has a rectangular shape in a cross-sectional view.

The material of the wire forming the coil body 43 may be the same as that of the coil body 3 of the first embodiment, and in the present embodiment, the same stainless steel is used for the tip-side coil body 43a and the base-side coil body 43 b.

As described above, the coating agent 47 covers the outer peripheries of the coil body 43 and the core shaft 9, but as shown in fig. 8, the coating agent 47 of the present embodiment has a greater film thickness in the region of the base-end side coil body 43b than in the region of the tip-end side coil body 43 a.

In the present embodiment, the difference between the film thickness of the region of the base-side coil body 43b and the film thickness of the region of the tip-side coil body 43a is also about several μm to 10 μm, but is exaggeratedly illustrated in fig. 8 for easy understanding.

In the present embodiment, the reason why the film thickness in the region of the base-side coil body 43b is thicker than the film thickness in the region of the tip-side coil body 43a is that the surface roughness of the base-side coil body 43b is larger than the surface roughness of the tip-side coil body 43 a.

Therefore, when the coating agent 47 is applied to the surface of the coil body 43, the film thickness of the region of the base-side coil body 43b automatically becomes thicker than the film thickness of the region of the tip-side coil body 43 a.

Further, the adhesion between the base end side coil body 43b and the coating agent 47 is increased, and the smoothness of the guide wire 40 can be improved.

On the other hand, by forming the coating agent 47 thinly on the distal end side coil body 43a on the distal end side of the coil body 43, the distal end flexibility of the guide wire 40 can be ensured.

Further, the same material as the coating agent 7 of the first embodiment can be used for the coating agent 47.

According to the guide wire 40 of the present embodiment, since the core wire 9, the coil body 43 covering the tip end portion of the core wire 9, and the coating agent 47 covering the outer periphery of the coil body 43 are provided, and the coil body 43 includes the tip side coil body 43a on the tip side and the base side coil body 43b arranged on the base end side of the tip side coil body 43a, the wire rod constituting the tip side coil body 43a is circular in shape in a transverse cross-sectional view, the wire rod constituting the base side coil body 43b is rectangular in a transverse cross-sectional view, and the wire rods constituting the tip side coil body 43a tend to be in point contact with each other, and thus the tip flexibility of the guide wire 40 can be further ensured.

In the present embodiment, the tip-side coil body 43a and the base-side coil body 43b are described as being made of the same stainless steel, but the hardness of the tip-side coil body 43a may be made lower than that of the base-side coil body 43b as in the second embodiment, a groove may be formed in the longitudinal direction of the wire rod constituting the base-side coil body 43b as in the third embodiment, or a known surface treatment method such as an injection process may be performed on the entire coil body 43 after masking the portion of the tip-side coil body 43a of the coil body 43 as in the first embodiment.

In this case, in addition to the effects of the guide wire 40 of the present embodiment, the effects of the guide wire of the first embodiment to the guide wire of the third embodiment can be obtained.

Description of the symbols

1. 10, 20, 30, 40-a guide wire, 2, 4-a brazing material, 3, 13, 23, 33, 43-a coil body, 3a, 13a, 23a, 33a, 43 a-a tip-side coil body, 3b, 13b, 23b, 33b, 43 b-a base-side coil body, 7, 17, 27, 37, 47-a coating agent, 9-a mandrel, 25-a groove portion.

Claims

1. A guide wire is provided with:

a mandrel;

a coil body covering the front end of the core shaft; and

a coating agent covering the outer periphery of the coil body,

the above-described guidewire is characterized in that,

the coil body includes a distal-side coil body on a distal side and a proximal-side coil body disposed on a proximal side of the distal-side coil body,

the surface roughness of the wire material constituting the base end side coil body is made larger than the surface roughness of the wire material constituting the tip end side coil body.

2. The guidewire of claim 1,

a groove portion is formed on the surface of the base end side coil body along the longitudinal direction of the wire rod constituting the base end side coil body.

3. The guidewire of claim 1 or 2,

the wire rods constituting the base-end side coil body have a rectangular shape in a cross-sectional view.

4. The guidewire of claim 3,

the wire material constituting the tip-side coil body has a circular shape in a cross-sectional view.